Detection of RASSF1A promoter hypermethylation in serum from gastric and colorectal adenocarcinoma patients

AIM:To evaluate the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal ad- enocarcinoma. METHODS:Methylation-specific polymerase chain reac- tion (MSPCR) was used to examine the promoter meth- ylation status of the serum RASSF1A gene in 47 gastric adenocarcinoma patients, 45 colorectal adenocarcinoma patients, 60 patients with benign gastrointestinal dis- ease (30 with benign gastric disease and 30 with benign colorectal disease), and 30 healthy donor controls. Apaired study of RASSF1A promoter methylation status in primary tumor, adjacent normal tissue, and postopera- tive serum were conducted in 25 gastric and colorectal adenocarcinoma patients who later were underwent sur- gical therapy. RESULTS:The frequencies of detection of serum RASSF1A promoter hypermethylation in gastric (34.0%) and colorectal (28.9%) adenocarcinoma patients were significantly higher than those in patients with benign gastric (3.3%) or colorectal (6.7%) disease or in healthy donors (0%) (P < 0.01). The methylation status of RASSF1A promoter in serum samples was consistent with that in paired primary tumors, and the MSPCR results for RASSF1A promoter methylation status in paired preoperative samples were consistent with those in postoperative serum samples. The serum RASSF1A promoter hypermethylation did not correlate with patient sex, age, tumor differentiation grade, surgical therapy, or serum carcinoembryonic antigen level. Although the serum RASSF1A promoter hypermethylation frequency tended to be higher in patients with distant metastases, there was no correlation between methylation status and metastasis. CONCLUSION:Aberrant CpG island methylation within the promoter region of RASSF1A is a promising biomark- er for gastric and colorectal cancer.

Identification and Characterization of Side Population Cells in Human Lung Adenocarcinoma SPC-A1 Cells

Objective：There has been an increasing interest in recent years in the role of stem cells.With an extensive understanding of their biology,a major role for stem cells in the malignant process has been proposed and the existence of cancer stem cells（CSCs） has been confirmed in hematopoietic malignancies and solid organ malignancies including brain cancer,breast,prostate,colon,and pancreatic cancer.Lung cancer is the leading cause of cancer mortality in most large cities of China.It is possible that lung cancer contains cancer stem cells responsible for its malignancy.The aim of this study is to identify,characterize and enrich the CSC population that drives and maintains lung adenocarcinoma growth and metastasis.Methods：Side population（SP） cell analysis and sorting were applied on human lung adenocarcinoma cell line and an attempt to further enrich them by preliminary serum-free culture before fluorescence activated cell sorting（FACS） was done.Stem cell properties of SP cells were evaluated by their proliferative index,colony-forming efficiency,tumorigenic potential,bi-differentiation capacity and the expression of common stem cell surface markers.Results：Lung cancer cells could grow in a serum-free Medium（SFM） as non-adherent spheres similar to neurospheres or mammospheres.The proportion of SP cells in cell spheres was significantly higher than that in cells grown as monolayers.SP cells had a greater proliferative index,a higher colony-forming efficiency and a greater ability to form tumor in vivo.SP cells were both CCA positive and SP-C positive while non-SP cells were only SP-C positive.Flow cytometric analysis of cell phenotype showed that SP cells expressed CD133 and CD44,the common cell surface markers of cancer stem cells,while non-SP cells only expressed CD44.Conclusion：SP cells existed in human lung adenocarcinoma cell lines and they could be further enriched by preliminary serum-free culture before FACS sorting.SP cells possessed the properties of cancer stem cells.

Successful recovery of COVID-19-associated recurrent diarrhea and gastrointestinal hemorrhage using convalescent plasma

Background: Gastrointestinal symptoms are not rare among coronavirus disease 2019(COVID-19) patients, but there have been no reports regarding convalescent plasma therapy for the recovery of gastrointestinal problems in COVID-19 patients.Case presentation: We present two cases of patients with COVID-19-associated recurrent diarrhea and positive fecal occult blood who successfully recovered after a one-time convalescent plasma administration.Conclusion: When COVID-19 patients develop recurrent or refractory gastrointestinal symptoms and fail to respond to the available treatment, alternative therapy with convalescent plasma administration may be considered.

Relationship of serum vitamin D levels with diabetic microvascular complications in patients with type 2 diabetes mellitus

Background:Vitamin D deficiency has been reported to be associated with diabetic microvascular complications,but previous studies have only focused on the relationship between vitamin D and specific complications.Therefore,we aimed to explore the relationship between vitamin D level and diabetic microvascular complications in general,including diabetic retinopathy(DR),diabetic nephropathy(DN),and diabetic peripheral neuropathy(DPN).Methods:This was a cross-sectional study of 815 patients with type 2 diabetes mellitus(T2DM).Clinical information and laboratory results were collected from the medical records.The relationship between vitamin D and the three diabetic microvascular complications was investigated.Results:The serum 25-hydroxyvitamin D(25[OH]D)level of patients with DPN and/or DN was significantly lower than that of T2DM patients without any microvascular complications(P<0.01).Univariate analysis showed that the 25(OH)D level was related to DPN and DN,but not DR.After adjustment,the 25(OH)D level was confirmed to be an independent protective factor for DPN(odds ratio[OR]:0.968,P=0.004)and DN(OR:0.962,P=0.006).The prevalence of DPN and DN increased significantly as the serum 25(OH)D levels decreased.Furthermore,patients with both DPN and DN had the lowest concentration of serum 25(OH)D(P<0.001),and the prevalence of macroalbuminuria increased more abruptly than that of microalbuminuria across the 25(OH)D tertiles.Among the patients with vitamin D insufficiency,those with DPN presented more comorbid macroalbuminuria than those without DPN(15.32%vs.4.91%;P=0.001).Conclusions:Vitamin D deficiency is independently associated with higher risk of DPN and DN,but not DR,in T2DM patients.Further,it may be a potential predictor for both the occurrence and severity of DPN and DN.